Many signal processing applications, for example, applications in video, audio, telecommunications and other areas, may require filtering of a digital signal to remove a dominant signal spike and/or speckle-type noise. Video alignment between a test image and a reference image for video-quality measurements is an exemplary field of practice wherein such errors may be encountered. Such errors also may be found in transmitted signals with bursty noise interference, speckle block errors due to compressed-video transmission errors and other areas known in the art. Filtering methods and systems that remove abrupt and/or intermittent errors without, or with reduced, distortion of the surrounding and/or superimposed desired signal may be desirable.